DbConfigManager holds the configuration parameters for an environment.
In general, all configuration parameters are represented by a ConfigParam
defined in com.sleepycat.je.config.EnvironmentParams and can be represented
by a property described in the top level example.properties.
This reproduces the bug described SR [#12641], also related to SR [#9543].
Note that allthough this is a JUnit test case, it is not run as part of the
JUnit test suite.